Aspartame Chemical Properties,Uses,Production

Artificial sweeteners

Aspartame is a kind of artificial sweeteners, belongs to the amino acid dipeptide derivatives, by the chemist developed ulcer drugs found in 1965. With low dosage, high sweetness (sweetness is 150 to 200 times of sucrose), good taste, enhance flavor of citrus and other fruits and reducing heat does not produce dental caries, toxicity than saccharin and other synthetic sweetening agent advantages, is widely applied to beverages, diabetic food and some slimming health food, our daily life to drink cola formula once containing the product.
Aspartame in the metabolic processes in the body and the main degradation products are phenylalanine, methanol and aspartic acid, does not enter blood circulation, and does not accumulate in the body, food for the health harmless. But due to metabolic defects in patients with phenylketonuria (PKU), excessive body phenylalanine can influence its development, so in patients with the disease to disable adding aspartame.

Neotame

Neotame is aspartate dipeptide derivatives, is a new product developed at a cost of $80 million by American newt company after aspartame, representing the latest achievements of sweetener research field. It is according to the human sweet receptor double hydrophobic binding hypothesis. In aspartame molecule with a hydrophobic groups and the formation of aspartame derivatives. It can also act on the human sweet receptor of two hydrophobic binding sites and therefore sweetness increased greatly, 6000 to 10000 times sweeter than sucrose, 30 to 60 times than Biasiba sweet .
It retains many excellent characteristics such as aspartame, pure sweet taste and good flavor enhancing properties distribution, no energy, no caries, stable in acidic medium. Moreover, it is still a lot better than aspartame in dry conditions, it has a longer shelf life; in neutral medium or instantaneous high temperature sterilization conditions, its stability greatly exceed aspartame, which can be used as a sweetener in baking. Neotame can also be used together with reducing sugar and aldehyde flavor without adverse reaction, its safety is better than aspartame and has been greatly improved. Due to its high sweetness, etc. Sweeter is lower than the cost of aspartame. Therefore, neotame has huge market potential. In December of 1998, neotame as food sweeteners status of application have been proposed in the United States, and some other countries for the certification work is in July 9, 2002 . The U. S. Food and Drug Administration (FDA) confirmed the neotame safety and functional type, currently is in March 10, worldwide more regulatory agency and national review in 2003, China's Ministry of Health approval for neotame as a sweetener used in all kinds of food.
The above information is edited by the Chemicalbook Han Ya.

Content analysis

Accurately take sample of about 300 mg, moves into a 150ml beaker, dissolve in 96% formic acid 1.5ml, and glacial acetic 60ml. with crystal violet solution (ts-74), with 0.1 mol/L HClO4 immediately titrate to the end of green. At the same time a blank titration and make necessary correction. Each mI.0.1mol/L perchloric acid is the equivalent of 29.43mg C14H18N2O5.

Toxicity

Entering the human body can quickly metabolic day aspartic acid and phenylalanine, two kinds of amino acids are absorbed, which does not accumulate in the organization. But phenylketonuria patients cannot use. Therefore it is necessary to specially marked. Every year in China about 1500~2000 benzene acetone urine disease in children born, after eating can be in vivo abnormal accumulation caused by brain damage, mental development retardation and epilepsy.
The ADI value is 0~40mg/kg (FAO/WHO, 2001). Contains two ketone piperazine ADI value is 0~7.5.
GRAS (FDA, 172.804,2000).

Use limits

GB 2760-2001: all types of food (except canned food), are limited to GMP.
FAO/WHO (1984): sweets 0.3%, gum 1.0%; beverage 0.1%, 0.5% of breakfast cereals, and used for the preparation of diabetes, hypertension, obesity, cardiovascular patients with low sugar, low calorie health food, dosage depends on the need to set. Can also be used as flavor enhancer.

chemical property

White crystalline powder, odorless, there is strong sweet, sweet and pure, sweetness of sucrose was 100-200 times. Melting point is 235℃ (decomposition). Amino acids is with the general nature. In dry conditions or pH value of 2 to 5 range, it is stability, strong acidic water solution can hydrolyzed to produce amino acid monomer, in neutral or alkaline conditions it can be cyclized to diketopiperazine. Solubility in water (25℃) is relevant to pH value, pH 7.0 was 10.2%, pH value 3.72 is 18.2%. At 25, isoelectric point is pH value of 5.2. Mice by oral LD50 > 10 g/kg Adl is 0~40mg/kg (FAO/who, 1994)

Uses

1.Asparagus sweet is artificial synthesis of low calorie sweeteners, often used with sugar or other sweeteners. It can be used for all kinds of food, according to the production need to use, the general dosage is 0.5g/kg.
2.It Is used as a food additive, high sweetness nutritive sweeteners.
3.Non nutritive sweeteners. Flavoring agents.
4.According to China GB2760-90 provisions for all kinds of food, the maximum amount of use as normal production needs. According to the FAO/WHO (1984) provisions for sweets, dosage of 0.3%, 1.0% gum, beverage 0.1%, 0.5% of breakfast cereals, and used for the preparation of diabetes, hypertension, obesity, cardiovascular patients with low sugar, low calorie health food, dosage depends on the need to set. Can also be used as a flavor enhancer.
Aspartame is a L-aspartic acid and L-phenylalanine (body needed nutrients) two peptide synthesis, can be completely absorbed by the human body metabolism, non-toxic harmless, safe and reliable, cool and refreshing taste like sugar, but is 200 times sweeter than sucrose, the heat is only 1/200 sucrose, eat no gingivae that does not affect the blood glucose, obesity, hypertension, coronary heart disease. The World Health Organization (WHO) and the United Nations Food and Agriculture Organization (FAO) identified as A (1) level of sweetener, has been in the world more than 130 countries and regions approved for use. Widely added in a variety of food, non-staple food and all kinds of hard and soft drinks, the use of aspartame has more than 4000 kinds of varieties. Can be used as food additives, high sweetness sweeteners with nutrition. Packing: 25 kg fibreboard drum, lined with plastic bag.

Methods of production

1. By L-aspartate and L-phenylalanine methyl ester condensation.
2. By L-aspartic acid and L-phenylalanine methyl ester hydrochloride condensation.
There are two kinds of synthetic and enzymatic synthesis.
enzymic synthesis ：
Department of chemistry, Wuhan University, Tao Guoliang, gave the following synthetic route:
The preparation of I : 0.5mmol benzyloxy carbonyl aspartic acid, 1.5mmol phenylalanine methyl ester hydrochloride and 2.5ml water were added to 25 ml Erlenmeyer flask, with ammonia to adjust the pH to 6, adding 7mg of thermophilic protease, at 40℃mixing reaction for 6h. Filter and washed with distilled water, and drying to obtain white solid (I) 0.29g, 95.6% yield, melting point is 116 to 118 ℃. Elemental analysis results: C 62.96%, H6.09%.N of 6.65%.
preparation of II: it will be joined the conical flasks 0.5g sample I and 20mL3mol/L hydrochloride 25ml and 45℃ in the mixing reaction for 0.5h. Filtration and washing with distilled water, drying to obtain 0.32g the product II, yield is 92%, melting point is 129 to 131℃. Elemental analysis results: C 61.45%, H 5.42% , N 6.82%.
Preparation of III will 0.2g palladium carbon catalyst (10%), 20 ml of glacial acetic acid, 5 ml of water add 100 ml three necked flask, hydrogenation activation 1.5h. Join 0.6g II 20 ml acetic acid dissolution and, at 30℃ stirring hydrogenated after 6h. the reaction is completed after filtration, catalyst with acetic acid washing 3 times; the filtrate and washings were concentrated under reduced pressure to dry, 15ml of benzene, continue to decompress and concentrate to dry white solid, and drying to obtain 0.38g the product III, and the yield was 92.3%, the melting point is 245 ℃. The elemental analysis results: C 55.63%, H6.23%, N 8.96%.
Chemical synthesis method
The aspartic acid and phenylalanine as raw material, by amino protection, anhydride, condensation, hydrolysis, neutralization and other steps of the synthesis. Different protecting groups, different methylated sequence can have a variety of different synthesis methods. Such as the use of formyl as protecting groups and after methyl esterification process route.Into a 250ml flask into 27mL 95% of the methanol and 0.2g oxidation of magnesium and magnesium oxide is dissolved, add 100ml 98% of acetic anhydride, at this time, the temperature gradually rose to 40 ℃, adding acid 67gL-aspartic, heated to 50℃, stirring reaction time 2.5h insulation and fill with 15mL98% acetic anhydride, temperature and reaction time 2.5h, join 16ml isopropanol and continue for 1.5h, the reaction after cooling to room temperature.
Put the inner anhydride materialized to join 1000ml flask, add 207mL ethyl acetate and 66Gl-phenylalanine, stirring 1.5h in 25 to 30℃, add the glacial acetic acid 126mL, continue to reflect 4.5h, the reaction after the end of the vacuum to remove the solvent and to the temperature of the reaction system 65℃ so far. Then add 35% hydrochloric acid methylmercury, heating to 60 ℃, return at the end of the reaction of the hydrolysis of 2h, atmospheric distillation until boiling temperature of 63℃ (reaction temperature of 73 degrees C) so far, adding methanol 180, to continue the distillation to the system temperature of 85 ℃ so far. After cooled to 25℃, the removal of the vacuum light group.
Adding 35% hydrochloric acid 54mL to the hydrolysis liquid, methanol 9mL and water 43mL. In 20 to 30℃for esterification reaction was then filtered, washed separation from α-APM hydrochloride. It dissolves in 600ml distilled water, to 40 to 50 ℃ of 5%~10% NaOH solution and to Ph=4.5. cooling below, filtering, washing to α-APM crude product, and then dissolved in 500 ml of methanol and water (volume ratio of 1:2) mixture. The cooling crystallization, filtration washing, vacuum drying 45% yield in terms of L-phenylalanine.
The Japanese scholars put forward a route without protection:
90g phenylalanine methyl ester hydrochloride is dissolved in 450mL water, 24g sodium carbonate neutralization, two vinyl chloride extraction and 2350mL obtained. Adding 9g phenylalanine methyl ester of acetic acid and methanol extracts 8mL, 15.2g aspartic anhydride hydrochloride added at-20 deg.c, stirring for 30min, hot water and sodium carbonate were added to 70~80 350mL C (5.7g) 300mL. solution with 150mL two vinyl chloride 2 remaining after extraction of phenylalanine methyl ester, water with dilute hydrochloric acid to adjust the Ph value to the 4.8. of the aqueous solution of paper electrophoresis measured with 18.2G (molar yield of 60%) and 6.1g (α-APM beta 20% molar yield) β--APM. This solution is vacuum concentration 100mL, plus.36% hydrochloric acid 30mL, set the refrigerator overnight. A-APM-HCl 21.3g Precipitation Crystallization (yield 58%), the crystallization of filtered and dissolved in 200mL water solution. Stirring at 50 ℃, with 5% sodium carbonate solution to adjust the Ph value to 4.8, and then place the refrigerator overnight in the analysis And filtering to obtain alpha APM crystallization) (43% yield). Crystal dissolved in 500ml water. In 45℃ by Dowex 1 x 4 (acetate) columns (1 x 20cm), and 20 ml of water flushing, effluent and washings together vacuum concentration, precipitation of alpha APM crystallization 11.2g. yield of 37%, melting point 235~236℃ (decomposition), than the rotation alpha D22 32.0 ℃ = 1, Cu Suanzhong. Elemental analysis results: 55.30% C, H 6.19%, n 9.36%.

Category

Toxic substances

Explosive hazard characteristics

Edible contact dermatitis.

Combustible hazard characteristics

Combustible; combustion produces toxic nitrogen oxide smoke

Chemical Properties

white powder or tablets

Uses

A dipeptide ester about 160 times sweeter than sucrose in aqueous solution. A non-nutritive sweetener.

Definition

ChEBI: A dipeptide composed of methyl L-phenylalaninate and L-aspartic acid joined by a peptide linkage.